Specifications

Release Notes for Cisco IOS Release 12.0 S

78-7130-11 Rev. B0

New and Changed Information

reports, if any. You then troubleshoot your multicast environment as normal, perhaps using the mtrace

command from the source to the Test Receiver. If the show command displays no error reports, the Test

Receiver is receiving test packets without loss or duplicates from the Test Sender.

Multicast Source Discovery Protocol

Platforms: Cisco 7200 series, Cisco 7500/RSP, Cisco 12000 series

Multicast Source Discovery Protocol (MSDP) connects multiple Protocol Independent Multicast (PIM)

sparse-mode (SM) domains. MSDP allows multicast sources for a group to be known to all rendezvous

points (RPs) in different domains. Each PIM-SM domain uses its own RPs and need not depend on RPs

in other domains. An RP runs MSDP over TCP to discover multicast sources in other domains.

An RP in a PIM-SM domain has an MSDP peering relationship with MSDP-enabled routers in another

domain. The peering relationship occurs over a TCP connection, where primarily a list of sources

sending to multicast groups is exchanged. The TCP connections between RPs are achieved by the

underlying routing system. The receiving RP uses the source lists to establish a source path.

The purpose of this topology is to have domains discover multicast sources in other domains. If the

multicast sources are of interest to a domain that has receivers, multicast data is delivered over the

normal, source-tree building mechanism in PIM-SM.

MSDP is also used to announce sources sending to a group. These announcements must originate at the

domain RP.

MSDP depends heavily on MBGP for interdomain operation. You should run MSDP in your domain

RPs that act as sources, sending to global groups for announcement to the Internet. See the following

document for futher information:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t7/msdp.htm

Multiprotocol Label Switching Traffic Engineering

Platforms: Cisco 7200 series, Cisco 7500/RSP series, Cisco 12000 series

Multiprotocol Label Switching (MPLS) traffic engineering software enables an MPLS backbone to

replicate and expand upon the traffic engineering capabilities of Layer 2 ATM and Frame Relay

networks. Traffic engineering is essential for service provider and Internet service provider (ISP)

backbones. Such backbones must support a high use of transmission capacity, and the networks must

be very resilient so that they can withstand link or node failures.

MPLS traffic engineering provides an integrated approach to traffic engineering. With MPLS, traffic

engineering capabilities are integrated into Layer 3, which optimizes the routing of IP traffic, given the

constraints imposed by backbone capacity and topology.

MPLS traffic engineering routes traffic flows across a network based on the resources the traffic flow

requires and the resources available in the network.

MPLS traffic engineering employs “constraint-based routing,” in which the path for a traffic flow is the

shortest path that meets the resource requirements (constraints) of the traffic flow. In MPLS traffic

engineering, the flow has bandwidth requirements, media requirements, a priority versus other flows,

and so on.

MPLS traffic engineering gracefully recovers to link or node failures that change the topology of the

backbone by adapting to the new set of constraints. See the following document for further information:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s5/mpl

s_te.htm